Women in the U.S. have made tremendous gains in education, employment and earnings in the past 50 years, but there is still a persistent gender pay gap. Even young working women continue to lag behind men. And, unfortunately, the gap tends to widen from graduation onward. Here are some sad facts about the gender wage gap that were summarized by The Center for American Progress from data compiled by the Census Bureau and the Bureau of Labor Statistics.

1. In 2010 women who worked full time, year round, still only earned 77 percent of what men earned. The median earnings for women were $36,931 compared to $47,715 for men, and neither real median earnings nor the female-to-male earnings ratio have increased since 2009.

2. The gender wage gap does not only affect individuals—entire families are impacted by women’s earnings. In 2010, in nearly two-thirds of families (63.9 percent), a mother was either the breadwinner—either a single working mother or bringing home as much or more than her husband—or a co-breadwinner—bringing home at least a quarter of the family’s earnings. When women’s wages are lowered due to gender discrimination, their families’ incomes are often significantly lowered as well.

3. Women earn less than men within all racial and ethnic groups. In 2010, the latest year for which data are available, white women earned 78.1 percent compared to white men, African American women earned 89.8 percent compared to black men, Hispanic women earned 91.3 percent compared to Hispanic men, and Asian women earned 79.7 percent compared to Asian men. The wage gap is lower for black and Hispanic women in part because wages for people of color tend to be lower overall. This gap occurs within racial/ethnic groups as well. In 2010, according to the Census Bureau, African Americans earned only 58.7 percent of what whites earned, while Hispanics earned only 69.1 percent of what whites earned.

4. Even though women are outpacing men in getting college degrees that’s not enough to close the gender pay gap. The American Association of University Women tackled the pay gap question by looking at workers of the same educational attainment—same kind of college, same grades—holding the same kinds of jobs, and having made the same choices about marriage and number of kids. They found that college-educated women earn 5 percent less the first year out of school than their male peers. Ten years later, even if they keep working on par with those men, the women earn 12 percent less.

5. Women are more likely to work in low-wage, “pink-collar” jobs such as teaching, child care, nursing, cleaning, and waitressing. The top 10 jobs held by women include: secretaries and administrative assistants (number one); elementary and middle-school teachers (number four); retail salespeople (number six); and maids and housekeepers (number 10). These jobs typically pay less than male-dominated jobs and are fueling the gender wage gap. These are also the “jobs of the future,” the kinds of jobs that the Department of Labor projects will grow faster than other occupations, so addressing the pay gap here will have long-term consequences.

6. The wage gap accumulates over time. Over a 40-year working career, the average woman loses $431,000 as the result of the wage gap. The pay gap accumulates in no small part because initial pay matters: If a woman earns less in her first job, when she takes a new job and her new employer sets her pay scale, they will often base it on her pay history. The lifetime wage gap for a woman who did not finish high school is $300,000, while the lifetime wage gap for a woman with at least a bachelor’s degree is $723,000. Making sure that young women understand the importance of negotiating for good pay from day one should be a pressing policy concern and is included in the Paycheck Fairness Act.

7. As women age the wage gap continues to grow. For working women between the ages of 25 to 29, the annual wage gap is $1,702. In the last five years before retirement, however, the annual wage gap jumps to $14,352.

8. Single women are even more adversely affected by the wage gap than married women. Single women earn only 78.8 percent of what married women earn, and only 57 cents for every dollar that married males earn.

9. More than 40 percent of the wage gap cannot be explained by occupation, work experience, race, or union membership. More than one-quarter of the wage gap is due to the different jobs that men and women hold, and about 10 percent is due to the fact that women are more likely to leave the workforce to provide unpaid care to family members. But even when controlling for gender and racial differences, 41 percent is “unexplainable by measureable factors.” Even if women and men have the same background, the wage gap still exists, highlighting the fact that part of the discrepancy can be attributed to gender-based pay discrimination.

There are pay discrimination laws on the books, but the continuing gender pay bias shows that enforcement is weak or lacking. The Lilly Ledbetter Fair Pay Act would help women and minority workers challenge discriminatory pay in the courts. The Paycheck Fairness Act would be an important step further and close the wage gap by prohibiting gender-based pay discrepancies and banning workplace policies that prohibit employees from disclosing their wages with each other. However, the measure has stalled in Congress and currently seems unlikely to even come to a vote in the House.

The gender pay bias is a form of discrimination as ugly as any America has experienced. It hurts the women who are its victims and the families they support. No society will ever achieve its full potential if it demeans and disenfranchises half of its population in this way.